液相色谱-串联质谱法检测食用油脂中多环芳烃

建立了有机溶剂萃取、硅胶固相萃取柱净化、液相色谱-串联质谱法(LC-MS/MS法)测定食用油脂中EPA 16种多环芳烃的检测方法。EPA 16种多环芳烃的定量限分别为0.02~0.43μg/kg,回收率为86.5%~104.6%,日内精密度小于6%,日间精密度小于5%。在40个受测油脂样品中,EPA 16种多环芳烃的含量范围为11.68~146.06μg/kg。对照我国GB 2716规定,所有受测样品中苯并(a)芘含量均不超过≤10μg/kg的限量标准。然而,8个油样的苯并(a)芘含量超过了欧盟≤2μg/kg的限量标准,10个油样的PAH4含量超过了欧盟≤10μg/kg的限量标准。     

食用植物油中痕量游离棉酚的超高效液相色谱-串联质谱测定

建立了超高效液相色谱-三重四级杆-串联质谱法(UPLC-ESI-MS/MS)测定食用植物油中游离棉酚的含量,以乙醇为提取溶剂提取食用植物油中的游离棉酚,采用Waters AQUITY UPLC BEH C18色谱柱进行分离,以乙腈-0.1%的甲酸水溶液作为流动相,梯度洗脱。在电喷雾离子源(ESI)负离子模式和多反应通道监测(MRM)模式下进行定量分析。结果表明:棉酚的质量浓度在0.005～5.0μg/mL范围内线性关系良好,方法检出限LOD (S/N≥3)为10μg/kg,定量限LOQ (S/N≥10)为50μg/kg。以0.25、2.5、25μg/g 3个不同棉酚浓度进行加标后测得平均加标回收率为80.3%～112.6%,相对标准偏差小于11%,精密度0.42%。该方法灵敏度高,测定结果准确,回收率稳定,适用于确证检测食用植物油中的棉酚残留。     

高效液相色谱串联质谱检测食用植物油中的乙基麦芽酚

为了建立食用植物油中乙基麦芽酚检测的高效液相色谱串联质谱方法,食用植物油样品与二氯甲烷混合后,以1.5%NaOH水溶液做为提取溶剂,涡旋、离心后,用磷酸将上层提取液调至4～7,调节pH后的上清液用PLS固相萃取柱进行净化除杂。采用电喷雾电离源正离子多反应监测模式进行检测,采用溶剂匹配标准曲线外标法进行定量。结果表明：该方法在6.25～100 ng/mL质量浓度范围内线性关系良好(R²>0.999),方法定量限为25.0μg/kg,在3个加标水平下的平均回收率为82.9%～105.1%,相对标准偏差小于5%,重复性好。该方法准确、灵敏度高,能有效减少芝麻油的基质效应,适用于多种食用植物油中乙基麦芽酚的检测。     

Determination of mycotoxins in cereals by liquid chromatography tandem mass spectrometry

A liquid chromatography tandem mass spectrometry (LC–MS/MS) method is described for simultaneous determination of aflatoxins (AFB₁, AFB₂, AFG₁ and AFG₂), ochratoxin A (OTA), zearalenone (ZEA), deoxynivalenol (DON), fumonisins (FB₁ and FB₂), T2 and HT2-toxin in cereals. One-step extraction using solvent mixtures of acetonitrile:water:acetic acid (79:20:1) without any clean-up was employed for extraction of these mycotoxins from cereals. The mean recoveries of mycotoxins in spiked cereals ranged from 76.8% to 108.4%. Limits of detection (LOD) and quantification (LOQ) ranged 0.01–20 and 0.02–40 ng/g, respectively. The developed method has been applied for the determination of mycotoxins in 100 cereal samples collected from Malaysian markets. A total of 77 cereal samples (77%) contaminated with at least one of these mycotoxins. Occurrence of mycotoxins in commercial cereal samples were 70%, 40%, 25%, 36%, 19%, 13%, 16, and 16% for aflatoxins, OTA, ZEA, DON, FB₁, FB₂, T2 and HT2-toxin, respectively. The results demonstrated that the procedure was suitable for the determination of mycotoxins in cereals and could be implemented for the routine analysis.     

Pesticide residues in fruits and vegetables in Jordan using liquid chromatography/tandem mass spectrometry

A total of 158 fruit and vegetable samples produced in Jordan were examined for the presence of pesticide residues using the multi-residue analysis technique by Liquid Chromatography-tandem Mass Spectrometry (LC-MS/MS) and the QuEchERS extraction method. A total of 73 samples (46%) were free from detectable residues, while 85 samples (54%) contained residues. Among the tested samples, 34 (22%) contained residues above Maximum Residue Levels (MRLs) and 51 (32%) contained residues at or below MRLs. Most of the detected residues were found in sweet pepper, peach and apricot samples. Only watermelon samples were free from detectable residues, while tomato and melon samples exhibited residues below MRLs. Out of the 113 pesticides tested, 22 pesticides were found above the limit of detection, 9 of which (hexaconazole, propargite, propiconazole, myclobutanil, thiamethoxam, thiacloprid, clothianidin, clofentezine and pyridaben) had residues that violate MRLs according to European regulations. A continuous monitoring programme for pesticide residues in Jordanian fruits and vegetables is highly recommended.     

Determination of selected mycotoxins in mould cheeses with liquid chromatography coupled to tandem with mass spectrometry

A simple and feasible method is described for analysing nine mycotoxins in cheese matrix. The method involves liquid extraction followed by high performance liquid chromatographic separation and mass spectrometric detection of the analytes, and allows the determination of aflatoxins B1, B2, G1, G2 and M1, ochratoxin A, mycophenolic acid, penicillic acid and roquefortine C simultaneously. Average recoveries of the mycotoxins from spiked samples at concentration levels of 5-200 µg kg^-1 ranged from 96-143%. Within-day relative standard deviations at these concentration levels varied from 2.3-12.1%. The limit of quantification for aflatoxin M1 was 0.6 µg kg^-1 and for the other compounds 5 µg kg^-1. The method developed was applied for analysing these mycotoxins in blue and white mould cheeses purchased from Finnish supermarkets. Roquefortine C was detected in all of the blue mould cheese samples in concentrations of 0.8-12 mg kg^-1. One blue cheese contained also 0.3 mg kg^-1 mycophenolic acid. The other investigated mycotoxins were absent in the samples.     

Multi-residue method for the analysis of pesticides in Arabica coffee using liquid chromatography/tandem mass spectrometry

Coffee is a major tropical agricultural commodity and represents a significant fraction of the economy of many countries. However, certain plant and animal species can damage coffee crops, affecting trade. A solution to this issue is the use of pesticides, some of which are harmful to human health and the environment. This work consisted of the development of a multi-residue method for the analysis of pesticides in coffee by using LC-MS/MS. The QuEChERS extraction procedure was used. The following analytical parameters were optimised: selectivity, analytical range, linearity, LOD, LOQ, precision (RSD%) and recovery of the method. The results showed that the method is selective, as they were linear in the range of 10.0–100.0 µg kg^?1. The sensitivity, recovery and precision were adequate for the multi-residue analysis of pesticides in coffee. The method was applied to the analyses of 15 Brazilian coffee samples.     

液相色谱-串联质谱技术在食品中抗菌药物残留分析中的应用

对液相色谱-串联质谱技术在食品中常用抗菌药物残留分析中的应用进展进行了综述,重点论述了近年来该技术在几种常用抗菌药物如β-内酰胺类、四环素类、大环内脂类、氨基糖苷类、酰胺醇类、磺胺类、喹诺酮类和硝基呋喃类的残留分析中的应用。同时,介绍了食品中多种类别抗菌药物残留同时检测的液相色谱-串联质谱方法,提出四极杆串联飞行时间质谱在多类别抗菌药物残留同时分析中具有广阔的应用前景,并对液相色谱-串联质谱技术在食品中抗菌药物残留分析领域未来的发展趋势进行了展望。      

超高效液相色谱-串联质谱法测定 食用植物油中的游离棉酚

目的 建立了超高效液相色谱一电喷雾串联质谱测定食用植物油中游离棉酚的方法。方法 样品采用无水乙醇溶液提取,C18色谱柱分离,电喷雾串联四极杆质谱仪进行检测。结果 棉酚的质量浓度在0.001μg ／mL~1.0 μ g ／mL 范围内具有良好的线性关系。食用植物油中的棉酚在5μg/kg、50μg/kg和250μg/kg 3 个添加水平下,平均回收率为68.9%~94.4%,相对标准偏差小于12.0%;方法间出限LOD（S/N ≥3 ) 为1μ g ／k g ,定量限LOQ( S/N ≥1 0 ) 为5μ g ／k g 。结论 该方法快速简单,结果准确,重现性好,适用于食用植物油中的游离棉酚含量的测定。     

Analysis of quinclorac and quinclorac methyl ester in canola from the 2015 harvest using QuEChERS with liquid chromatography polarity-switching tandem mass spectrometry

A method using QuEChERS sample preparation with liquid chromatography polarity-switching tandem mass spectrometry was developed and validated for the analysis of quinclorac and its degradation product quinclorac methyl ester in canola seed. The method was used to analyse canola treated with quinclorac, harvest sample composites and samples of canola shipments. Quinclorac residues were present in all samples of canola treated with a quinclorac-containing herbicide that were analysed. Quinclorac was found in 93% of samples, with an average of 0.018 mg kg^–1. All samples contained quinclorac methyl ester, with an average of 0.061 mg kg^–1. The average concentration of total residues (as quinclorac equivalents) on treated canola was 0.075 mg kg^–1, with a range of 0.016–0.124 mg kg^–1. The observed residues were all at least 10 times lower than the Canadian maximum residue limit of 1.5 mg kg^–1. Quinclorac and quinclorac methyl ester were not found in any harvest and export composite samples, which represented the majority of canola grown in western Canada in 2015 and canola exported in late 2015. Even though usage of quinclorac-containing herbicide on canola can result in the presence of low concentrations of residues, the absence of quinclorac residues in harvest and shipment samples suggests that use of quinclorac-containing herbicide was not widespread, and that any residues present were diluted as canola was combined along the grain-handling chain into shipment lots, or segregated and prevented from entering shipment lots.     

Multiresidue method for detection of pesticides in beef meat using liquid chromatography coupled to mass spectrometry detection (LC-MS) after QuEChERS extraction

Beef meat is an important food that can be contaminated by pesticides. This study aimed to optimize a multiresidue method for identification and quantification of pesticides in beef meat by liquid chromatography coupled to mass spectrometry detection (LC-MS). The extraction and clean-up procedures were adapted from the QuECHERS method. From the 188 analytes tested, the method was validated as qualitative method for 19 compounds and as quantitative method for 152 compounds. The results were satisfactory, yielding coefficients of variation of less than 20% and recoveries ranging from 70% to 120% and expanded uncertainty of less than 50%. The quantification limit was typically 10 µg kg^?1 (but 25 µg kg^?1 for 12 of the compounds) and the detection limit was 5.0 µg kg^?1. Thirty-two real samples of commercialized beef meat were analyzed without any residual pesticide being found. Thus, the results showed that the multiresidue method for detecting 171 pesticides, using adapted QuECHERS for extraction and LC-MS for detection, is suitable for analyzing beef meat.     

高效液相色谱－串联质谱法测定桃仁中 10种真菌毒素

目的 建立了桃仁中黄曲霉毒素G2、G1、B2、B1、赭曲霉毒素A、呕吐毒素、玉米赤霉烯酮、伏马毒素B1、B2及T-2毒素10种真菌毒素的液相色谱－串联质谱测定法。方法 样品经70%甲醇溶液超声提取,用水稀释后经HLB柱净化,经C18色谱柱分离,以电喷雾离子源在正负离子多反应监测(MRM)模式下测定,外标法定量。结果 10种真菌毒素的线性关系良好,γ＞0.995。回收率在60％～100％之间。结论该法快速简便,准确,可用于中药材中真菌毒素的多成分残留测定。     

超快速液相色谱-串联质谱法测定粮食及食用油中的黄曲霉毒素

应用超快速液相色谱―串联质谱法技术,建立粮食及食用油中黄曲霉毒素的检测方法,并对宁夏市售小麦粉、玉米制品和食用油进行分析。样品经乙腈―水(20︰80)提取,免疫亲和柱净化;以甲醇–0.1%甲酸水溶液为流动相,用Atlantis T3色谱柱分离,以电喷雾正离子模式进行质谱测定。采用该方法,黄曲霉毒素B1、B2、G1和G2可在6分钟内完成检测,分别以小麦粉、玉米制品和食用油为加标基质,三个加标水平下的平均回收率为75.6%~94.1%,相对标准偏差小于10.0%,检出限(S/N=3)为0.05μg/kg,定量限(S/N=10)为0.15μg/kg。该方法操作快速简单、重现性好,可用于粮食中黄曲霉毒素B1、B2、G1和G2的检测。     

Development and validation of rapid multiresidue and multi-class analysis for antibiotics and anthelmintics in feed by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry

A new multi-residue method for the analysis of veterinary drugs, namely amoxicillin, chlortetracycline, colistins A and B, doxycycline, fenbendazole, flubendazole, ivermectin, lincomycin, oxytetracycline, sulfadiazine, tiamulin, tilmicosin and trimethoprim, was developed and validated for feed. After acidic extraction, the samples were centrifuged, purified by SPE and analysed by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry. Quantitative validation was done in accordance with the guidelines laid down in European Commission Decision 2002/657/CE. Matrix-matched calibration with internal standards was used to reduce matrix effects. The target level was set at the authorised carryover level (1%) and validation levels were set at 0.5%, 1% and 1.5%. Method performances were evaluated by the following parameters: linearity (0.986 < R² < 0.999), precision (repeatability < 12.4% and reproducibility < 14.0%), accuracy (89% < recovery < 107%), sensitivity, decision limit (CCα), detection capability (CCβ), selectivity and expanded measurement uncertainty (k = 2).This method has been used successfully for three years for routine monitoring of antibiotic residues in feeds during which period 20% of samples were found to exceed the 1% authorised carryover limit and were deemed non-compliant.     

Quantitative analysis of Fusarium mycotoxins in maize using accelerated solvent extraction before liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometry

A method for the simultaneous quantitative determination of deoxynivalenol (DON), fumonisin B1 (FB1) and zearalenone (ZEN) in maize by liquid chromatography-atmospheric pressure chemical ionization tandem mass spectrometry (LC-APCIMS/MS), using stable isotopically labelled and structural analogues internal standards, is described. The procedure involves accelerated solvent extraction followed by two solid-phase clean-up steps on strong anion exchange resin and a Mycosep® column. Typical recoveries were calculated by spiking blank maize at three different concentrations for deoxynivalenol (200, 400 and 1000 μg kg^-1) at 70%, for fumonisin B1 (100, 200 and 1000 μg kg^-1) at 90%, and for zearalenone (50, 100 and 200 μg kg^-1) at 40%. LC-APCIMS/MS analyses were realized in collision-induced dissociation on an ion-trap instrument to provide a high degree of selectivity and sensitivity. Extraction of ions from two transition reactions, monitored by LC-APCIMS/MS for each analyte, enabled a limit of detection for DON, FB1 and ZEN at, respectively, 10, 20 and 3 μg kg^-1, and a limit of quantification at, respectively, 50, 50 and 10 μg kg^-1. The robustness of the method was also evaluated with the analysis of wheat samples.     

Acrylamide levels in Finnish foodstuffs analysed with liquid chromatography tandem mass spectrometry

Sample clean-up and HPLC with tandem mass spectrometric detection (LC-MS/MS) was validated for the routine analysis of acrylamide in various foodstuffs. The method used proved to be reliable and the detection limit for routine monitoring was sensitive enough for foods and drinks (38 microg/kg for foods and 5 microg/L for drinks). The RSDs for repeatability and day-to-day variation were below 15% in all food matrices. Two hundred and one samples which included more than 30 different types of food and foods manufactured and prepared in various ways were analysed. The main types of food analysed were potato and cereal-based foods, processed foods (pizza, minced beef meat, meat balls, chicken nuggets, potato-ham casserole and fried bacon) and coffee. Acrylamide was detected at levels, ranging from nondetectable to 1480 microg/kg level in solid food, with crisp bread exhibiting the highest levels. In drinks, the highest value (29 microg/L) was found in regular coffee drinks.     

Determination and quantification of the emetic toxin cereulide from Bacillus cereus in pasta,rice and cream with liquid chromatography–tandem mass spectrometry

A rapid and sensitive method has been developed for determination and quantification of cereulide in cream, rice and pasta. Samples are homogenised after addition of amylase to cooked rice and pasta, and cereulide is extracted with methanol. After the removal of water with methyl-tert butyl ether/hexane and evaporation until dryness, no further purification was required before analysis with liquid chromatography–tandem mass spectrometry (LC-MS/MS). Recently, both cereulide and ¹³C₆-cereulide has become commercially available at high purities; hence, this method offers a more reliable quantification of positive samples than previous methods using valinomycin or in-house produced and purified cereulide as calibration standard. The introduction of amylase in the sample preparation improves both the extraction yield of cereulide from positive samples of starch-rich matrices such as pasta and rice, and the within-laboratory reproducibility of the analytical method. The LoQ of the method is 1.1 ng/g cereulide with RSDs ranging from 2.6% to 10%. The method is fully validated based on Commission Decision 2002/657/EC, suitable for routine analysis, and has been used to analyse samples from a cereulide food poisoning outbreak in a kindergarten in Norway. Cereulide production in different rice and pasta samples was investigated, showing that cereulide was unexpectedly produced by emetic Bacillus cereus in all eight pasta and rice samples.     

Quantitative analysis of acrylamide in tea by liquid chromatography coupled with electrospray ionization tandem mass spectrometry

An effective sample preparation procedure was optimized and a liquid chromatography–tandem mass spectrometry (LC–MS/MS) was developed for the quantitative analysis of acrylamide in tea. [¹³C₃]-acrylamide was used as internal standard. Acrylamide was extracted at 25 °C for 20 min by 10 ml water followed by 10 ml acetonitrile, and then 4 g of magnesium sulfate and 0.5 g of sodium chloride were added to the above mixture under stirring thoroughly. In order to increase the response of acrylamide, 9 ml acetonitrile layer was taken and concentrated to 0.5 ml. Solid-phase extraction with an Oasis MCX cartridge was carried out for clean-up. The limit of detection (LOD) and limit of quantification (LOQ) were 1 and 5 ng/ml, respectively. The recovery efficiency of the extraction procedure ranged between 74% and 79%. The levels of acrylamide in 30 tea samples were less than 100 ng/g. Black, oolong, white and yellow tea samples had quite low acrylamide contents (<20 ng/g). Higher acrylamide levels occurred in baked, roasted, and one sun-dried green tea samples (46–94 ng/g).     

Fast analysis of glufosinate,glyphosate and its main metabolite,aminomethylphosphonic acid,in edible oils,by liquid chromatographycoupled with electrospray tandem mass spectrometry

ABSTRACT

A method has been developed for the rapid, specific, accurate, precise and sensitive determination of glufosinate, glyphosate and its major metabolite, aminomethylphosphonic acid, in edible oils, by liquid chromatography coupled to tandem mass spectrometry. Oils were extracted with acidified water (1% formic acid), and the extracts were directly injected into an LC using a Hypercarb column as the stationary phase. The analytes were eluted by a mobile phase of methanol and water containing 1% acetic acid, and they were ionised by electrospray ionisation in negative ion mode. The method was validated and limits of quantification ranged from 5 μg kg^?1 (aminomethylphosphonic acid) to 10 μg kg^?1 (glyphosate and glufosinate). Three concentrations (10, 50 and 100 μg kg^?1) were selected to perform recovery studies. Mean recoveries ranged from 81.4% to 119.4%. Intra and inter-day precision were lower than 19%. Different edible oils were analysed, and no residues of the studied herbicides were detected above limits of quantification.     

Quantifying fenobucarb residue levels in beef muscles using liquid chromatography–tandem mass spectrometry and QuEChERS sample preparation

This paper describes a comparison of the properties of the three versions of the QuEChERS method (quick, easy, cheap, effective, rugged and safe) – the original (unbuffered), acetate-buffered, and citrate-buffered methods – for the determination of fenobucarb residues in beef muscles via liquid chromatography–electrospray ionisation tandem mass spectrometry (LC–ESI⁺-MS/MS). The recovery results were good for all the versions; however, the acetate-buffered version gave higher and more consistent recoveries for fenobucarb than the other versions. Performance characteristics, such as linearity, accuracy, and precision were determined. Matrix-matched standard calibration was used for quantification, obtaining recoveries in the range of 83.7–93.4% with relative standard deviations of <5%, at two spiking levels: 10 and 40 μg/kg. The limits of detection (LOD) and quantification (LOQ) were estimated to be 1.5 and 5 μg/kg, respectively. Finally, the method was applied to the analysis of 15 market samples, and no residues were found over the limit of quantification. The method developed was found able to determine the analyte with satisfactory intensity and accuracy.